What Does a Knuckleball Do?

By

Christopher Shea

Jun 7, 2012 12:09 pm ET

Nick Laham / Getty Images

Tim Wakefield, one of the most successful knuckleball pitchers in recent years.

I thought I knew, but this cool Washington Post graphic says I’m wrong: Knuckleballs don’t flutter — that they appear to may be the result of an optical illusion, says the neuroscientist Arthur Shapiro. They “stick to their trajectory nearly as closely as every other type of pitch.” It’s simply (or not-so-simply!) that this trajectory varies unpredictably from throw to throw.